摘要
改性生物炭具有较大的比表面积、可调节的孔隙结构和丰富的活性功能位点,使其能有效去除环境中的抗生素,但比较改性生物炭的不同性质对抗生素吸附降解的贡献缺乏系统研究.为明确金属浸渍改性生物的持久性自由基(PFRs)和微孔结构对环丙沙星(CIP)的吸附降解的贡献差异,在500℃和800℃热解条件下,制备了Ni改性和Zn改性的生物炭.500℃Ni改性(NCS500)明显提升了生物炭表面PFRs信号强度,而800℃Zn改性生物炭(ZCS800)比表面积得到显著提升(1 030.94 m^(2)·g^(-1)).与未改性生物炭相比,NCS500和ZCS800能够提高对CIP的最大吸附容量,使其分别达到78.68 mg·g^(-1)和190.07 mg·g^(-1),比对应的原始生物炭提升了3.35倍和24.83倍.乙腈萃取实验可区分两种改性生物炭CIP降解率在总去除率中的占比,Ni改性生物炭降解率最高,占总去除率的74.67%;而Zn改性生物炭的总去除率最高,但降解率仅占总去除率的52.63%,这是因为两种金属盐浸渍改性生物炭能产生羟基自由基(·OH)等活性氧物质有效降解CIP,但Ni改性生物炭其表面突出的PFRs信号能进一步直接与CIP反应高效降解CIP,而Zn改性生物炭较高的比表面积有利于疏水相互作用和π-π电子供体-受体与芳香分子的相互作用,显著提高了CIP的吸附.
Modified biochars have a large specific surface area,a tunable pore structure,and abundant active functional sites,which enable them to effectively remove antibiotics from the environment.However,systematic research on the contribution of different properties of modified biochars to the adsorption and degradation of antibiotics has not been carefully investigated.To clarify the contribution of adsorption and degradation of ciprofloxacin (CIP) by persistent free radicals (PFRs) and the microporous structure of metalimpregnated modified biochars during the removal process,nickel-modified and zinc-modified biochars were prepared under pyrolysis conditions of 500℃and 800℃,respectively.Nickel-modified biochar pyrolyzed at 500℃(NCS500) significantly improved the PFR signal intensity,while the specific surface area of zinc-modified biochar pyrolyzed at 800℃(ZCS800) was significantly increased (1 030.94 m~2·g~(-1)).The maximum CIP adsorption capacity of NCS500 and ZCS800 increased dramatically,reaching 78.68 mg·g~(-1) and 190.07mg·g~(-1),respectively,which was 3.35 times and 24.83 times higher than the corresponding values of the original unmodified biochar.The oxygen-containing functional groups such as carboxylic acid,hydroxyl group,and carbonyl group on the NCS500 were responsible for CIP adsorption due to the ion exchange,electrostatic interaction,surface complexation,and hydrogen bonding provided by carbonate components.The formation of a relatively stable graphite structure on the surface of ZCS800 was conducive to hydrophobic interaction,π-πelectron donor-acceptor interaction with aromatic molecules,and enhancing the adsorption of CIP.The acetonitrile extraction experiment could distinguish the adsorption and degradation contributions of the two modified biochars in the process of CIP removal,and the amount of CIP degradation by NCS500 could account for 74.67%of the total removal.The total CIP removal by ZCS800 was the highest,but the amount of CIP degradation accounted for only 52.63%of the total removal.This was because these two metal salt-impregnated modified biochars could produce active oxygen species such as hydroxyl radicals to effectively degrade CIP,while the PFRs signal on the surface of NCS500 could also directly react with CIP to effectively degrade CIP.The Zn-modified biochar was conducive to hydrophobic interactions,π-πinteractions,and aromatic molecule interactions,which significantly improved the adsorption of CIP.
作者
张静
江豪
杨晓宇
段文焱
陈芳媛
ZHANG Jing;JIANG Hao;YANG Xiao-yu;DUAN Wen-yan;CHEN Fang-yuan(Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control,Faculty of Environmental Science&Engineering,Kunming University of Science&Technology,Kunming 650500,China)
出处
《环境科学》
北大核心
2025年第2期923-933,共11页
Environmental Science
基金
国家自然科学基金地区科学基金项目(42267003)
云南省重大科技项目(202202AG050019)。
